/**
 * 算数运算符
 */

 var i = 3;
 var j = 8;

 document.write( j + i);
 document.write('<br/>');
 document.write(j - i);
 document.write('<br/>');
 document.write(j * i);
 document.write('<br/>');
 document.write();
 document.write('<br/>');
 document.write();
 document.write('<br/>');
 document.write();
 document.write('<br/>');
 document.write();
 document.write('<br/>');